The regs are somewhat clear on this. You must wear at least ONE exterior garment (hat,shirt,jacket,coat,vest or sweater) that is visible and fluorescent orange in color. The regs specifically state that fluorescent orange camouflage is legal. There is no percentage or inches requirement. I used to wear only a blaze orange bandanna around my neck. I was checked a few times with the bandanna and nothing was ever said. 2-3 years ago, a warden told me that it wasn't enough. I told him it was a vest. He said it wasn't a vest and I inquired as to where in the regs the word "vest" was defined. He was stumped by the question. I know of one young guy who has an old blaze orange ballcap pop riveted to the back of his pack. Do what you think is best and wear at least one of the garments in the regs. Remember, the regs don't say "pants".
mh